25 hp Johnson - bust

[Johnny]

Well folks,
With so much help from here on how to do minor repairs on my old 1979 25hp Johnson,
I am at my wits END !!!

Here is what I have done so far:
removed head and cover
new thermostat
new water deflectors (correctly installed)
new gaskets with Permatex
new exhaust manifold gaskets (on side of the motor) with Permatex
removed old 35hp carb - back to the original 25hp
new carburetor gasket kit
new flywheel key
bunch of new wires
all new fuel hoses and fittings and clamps, new inline fuel filter
new fuel pump gaskets

Cranked right up, idled well once warmed up.
lot of white smoke (which I think is normal)
No excess oil in exhaust
water pump works great
everything I took off, I replaced gaskets with new & Permatex

after all this .... I STILL HAVE WATER ON MY SPARK PLUGS !!!!!!!!!!

I have NO idea as to where it could be coming from.......
:x I think it is time to drop it off at the boat repair shop and let the PROFESSIONALS fix it !!!!! :x

 

[Charger25]

My guess is that the head needs to be milled flat. I got mine done for about 40 bucks

 

[santeerangerman]

Charger25 » 07 Aug 2014, 20:49[/url]"]My guess is that the head needs to be milled flat. I got mine done for about 40 bucks

Yep, it does sound like a head problem.

IF you have access to a surface plate, check the flatness with feeler gages. I've "heard" that a mirror will work in a jam, but I've never tried it.
The next part does work. I've done it myself several times. Latest was reworking a set of heads off a V-twin Kawasaki Mule...
Take a mirror and glue a sheet of 240grit wet/dry emory cloth to it. Add some light machine oil to the emory cloth, and proceed to sand the heads. Rotate the head every couple strokes. Don't sand in the same direction the whole time. Keep a even pressure as you work the head on the paper. No need to rush it. IT will get them flat, within .0015" if you take your time.

 

[jasper60103]

Just curious. Whats your compression?

 

[Johnny]

LOL - I know this will sound just plain WRONG ! BUT, I have lapped many a head
LOL see, i told you LOL

yes, I lapped the head and cover on a granite kitchen counter top and they are true flat.
did the same with the Side Exhaust Covers. They are also true flat.
I have a very flat and true metal file that I dressed the surfaces of the motor and they are true flat and clean.

today, I will remove the Side Exhaust Cover to double check the seal and will replace the gaskets.

As for the compression, I used my neighbors tester and it tested 90 psi in each cylinder
with the throttle CLOSED.
I did not know to have it WOT until after I returned the tester and read it on here about the open throttle.

so I am thinking I missed something on the Side Ex Covers.


and as Clint said - - - I will finish out this summer, then sell it and let it become someone else's PROJECT

 

[Natedog57]

I ask out of curiosity, what does the water on the plugs look like?

Is it possible the gas is bad? Are you using non-ethanol?

I've had an engine run poorly with gas that looked good and was run through a fuel/water filter (I even drained some from the inspection bowl)... changed to non-eth and it ran like a champ.

 

[Johnny]

I did that first before even firing it up.
fresh gas, fuel lines bled of old gas
in line fuel filter was empty

I will give update next week after installing new gaskets.

 

[JoshKeller]

do you have any oil residue at all on the plug? in my experience, if youre truely getting water in the cylinder, it'll be squeaky clean with no oil. another possibility is theres is a hairline crack or manufacturing defect in the block and it expands as it warms up and allows water through.

 

[Johnny]

Josh states the worst case scenero !!
there may be a hairline crack or manufacturing defect in the block and it expands as it warms up and allows water through.

nooooooo worst nightmare there !!!!

I replaced the exhaust cover gaskets, all mating parts are flat and true and CLEAN.

Ran the motor in a bucket for 15 full minutes at different RPMs and there is still clean water on the plugs.
As the photos show, no black oil or fowling other than the water.
It does however, run remarkably smooth even with the water on the plugs !!! no cutting out or sputtering,
which I find surprising. Just imagine how smooth this thing will run after it is FIXED !!!
so, I will remove the lower body and replace the "Powerhead to Lower Unit" gasket as it is
very obviously leaking and pouring water out of that area. Hopefully, this will be the last issue to deal with.
if it leaks after that, I am afraid it may call for a new powerhead. :x
Looking at new blocks now - LOL - on ebay.

 

[waterman]

You said it is smoking "white", that's probably steam. My guess is a crack somewhere. Hopefully not , maybe it's the powerhead gasket.

 

[Keith1]

I had that problem on a 25 hp Mariner and it was the lower crankshaft seal.

Regards, Keith

 

[JoshKeller]

pull the lower unit, remove thermostat, and hook up the waterhose to the water inlet and see if you can pinpoint where its leaking. much easier to do if you have a small camera to look down into the spark plug hole. if its a steady leak, you should be able to hear it after the block has filled with water and the motor not running. is the water entering both cylinders or just one?

 

[jasper60103]

Any update?

 

[Johnny]

yeah, the update is . . . . . I am so sick and tired of this stupid motor that
it is being pushed so far back on my back burner of things to do, it may never see
daylight again. . . . . . . .
I will piddle with my 1952 Ford 8N tractor for awhile.
work on my salt water tackle box, rods n reels, build some bottom rigs.
build me another PVC surf fishing cart to haul all my gear to the beach.
finish some electrical wiring in my house that I have put off for months.
track down and shoot two coyotes that are killing my chickens.
yada yada yada



that is my update.


For Sale: 1979 Johnson 25hp with ISSUES: $450.00

 

[New River Rat]

Barefoot_Johnny » 50 minutes ago[/url]"]

things to do

I will piddle with my 1952 Ford 8N tractor for awhile.

track down and shoot two coyotes that are killing my chickens.

These two would top my list!